When on campaign, the armies of the ancient world expected to live off the land by purchasing food and pillaging enemy territory. This made them especially vulnerable to scorched earth tactics, where defenders would purposely destroy crops to starve invaders. While naval vessels were able to deliver supplies, their use limited armies to coastal expeditions and it was not until the development of new, land-based supply methods that warfare changed significantly. These methods increased the efficiency and self-sufficiency of armies and provided a significant advantage over enemies, as evidenced by the success of the reformed Roman Legions.
